Abstracts


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Novel polymer-ceramics for bone repair and regeneration
Tran R.T., Zhang Y., Gyawali D.and Laurencin C.T.

Bone is composed primarily of an inorganic mineral phase of calcium phosphate and an organic phase of collagen. Reconstruction of large bone defects resulting from trauma, pathological degeneration, or congenital deformity is a significant medical challenge. Due to the limited availability and potential immunogenicity associated with autografts and allografts, tissue engineering has emerged as an alternative strategy to repair, restore, and regenerate lost or damaged tissues using biomaterials, cells, and factors alone or in combination. Polymers, ceramics, and their composites have been widely investigated as biomaterials for the development of synthetic bone graft substitutes. Specifically composites of biodegradable polymers and bioactive ceramics are attractive candidates that closely match the desirable properties of an autograft tissue (e.g. osteoconductivity and osteoinductivity). Composites can be fabricated into a variety of threedimensional (3D) porous structures or matrices to encourage bone regeneration. They can be further enhanced by incorporation of various factors or cells to promote bone healing. Recent advances in nanotechnology have allowed for the fabrication of nanocomposites in the form of particles or nanofibers that mimic the hierarchical arrangement of native bone. Present review focuses on bone repair/regeneration strategies using polymer-ceramic composites and highlights some of the recent important patents in the areas of tissue engineering and orthopedic devices. A basic overview of the physicochemical, structural and biological elements of bone is described to provide design considerations for clinically viable bone graft substitutes. Challenges in the development of tissue-inducing materials capable of eliciting precise control over cellular functions are also discussed.

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Production of recombinant proteins in bacteria: The inclusion bodies formation and their use in biomedicine
Peternel S. and Liovic M.

Four decades have passed since the first recombinant protein, somatostatin, was produced in Escherichia coli. To date, more than 160 biopharmaceuticals gained medical approval. As there is an increasing demand for new proteinbased biopharmaceuticals and proteins used in diagnostics, novel or improved host organisms and expression systems are constantly being developed. Nevertheless, E. coli is still one of the most commonly used organisms for the production of recombinant therapeutic proteins. Despite many improvements of E. coli expression system, one major setback is protein aggregation and inclusion bodies (IBs) formation. These often cannot be prevented from forming during recombinant protein production. For a long time IB formation represented a problem in protein production. However, recent studies on bacterial cultivation and protein aggregation revealed that friendlier bacterial cultivation leads to production of non-classical IBs (ncIBs), which are composed of properly folded and biologically active proteins. Such active ncIBs can be used either for protein isolation (production) or as active nanoparticles. Since the field of nanobiotechnology is evolving fast, a further development of the use of active IBs is expected.

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A review of patents on implantable heart-compression/assist devices and systems
Shahinpoor M.

This paper presents and discusses a number of significant seminal patents on implantable heart-assist and compression devises. It further discusses active, electrically controllable and implantable heart compression/assist systems equipped with ionic polymeric artificial muscles. A brief description of the characteristics and modeling of ionic polymer metal composites (IPMCs) as artificial muscles is also included in this paper. These polymeric artificial muscles can be suitably integrated with or sutured to the myocardium. In particular, they can be sutured to the left ventricle and placed around a failing heart's ischemic muscle tissues and snugly conformed to the size and the shape of the heart muscle to cyclically and synchronously assist the systolic and diastolic activities and functions of a failing heart. These systems will be designed for selectively assisting the ventricles or atria, and in particular the left ventricle of a weak heart to produce enough internal pressure and to pump blood from one or more sides in synchrony with the natural systolic contraction of the ventricle, as well as providing arrhythmia control of the beating heart. The proposed compression heart assist system is microprocessor based and electrically-controlled and completely implantable in the body of a patient for treating congestive heart diseases and related cardiac complications such as cardiomyopathy and valvular disorders. The same technology can also be applied to atrial fibrillation which is a malfunction of the right atrium as well other bio-organ compression such as thrombo-embolic deterrent (TED) type enhancement of venous circulation in the legs. The power supply for the implanted system can be multi-year long lasting batteries that can be recharged transcutaneously. The proposed multi-fingered heart compression device (MFHCD) is entirely endoscopically implantable and can be directly or transcutaneously energized by inductive magnetoresonant generators.

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Mobile phone based biomedical imaging technology: A newly emerging area
Xie Q.-M. and Liu J.

The operational complexity and extremely high cost in a conventional biomedical imaging device usually prevent patients from monitoring their health conditions or obtaining primary diagnosis themselves via a cheap and flexible way. The increasing demand for convenient medicine at low cost has significantly stimulated the innovations in extending the capabilities of a mobile phone as a basic tool in biomedical imaging area, whose low cost and easy access make it a rather perfect option for miniaturization and simplification of conventional medical devices. Combined with other technologies, the mobile phone is playing an increasingly important role in biomedical diagnosis and treatment owing to its imaging function. Such newly emerging frontier raises many challenging fundamental as well as very practical issues waiting for solving. Based on reviewing recent patents and some related researches, this article is dedicated to drafting this new biomedical imaging area and presenting a comprehensive evaluation on the latest achievements on developing the mobile phone based biomedical imaging technology. Important issues either in theory or hardware designs will be presented. Some important technical investigations worth of pursuing in the near future will be suggested. Particularly, direct optical or functional image acquisitions enabled from mobile phones will be illustrated with typical implementations in teledermatology, telemedicine, microscope, endoscope and ultrasound, X-CT, infrared, ECG mapping, biometric authentication, etc. Remote image detection using mobile phone as the imaging terminal is also proposed. Challenges for further development will be pointed out. From the technical routes as clarified and outlined in the present article, it can be found that there is plenty of space in the coming era of mobile phone based biomedical imaging technology.

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Recent developments on citric acid derived biodegradable elastomers
Tran R.T., Zhang Y., Gyawali D.and Yang J.

Biodegradable elastomers have recently found widespread application in many areas of biomedical engineering such as tissue engineering, drug delivery, and bioimaging. In particular, the recent developments in research have led to the creation of citric acid based polymers with enhanced mechanical properties, novel design strategies for crosslinking, nanoporous features, and unique photoluminescent capabilities. The present review will cover the recent patents involving citric acid derived biodegradable biomaterials within the field of biomedical engineering including poly (diol citrates) and their composites, crosslinked urethane-doped polyesters (CUPEs), poly (alkylene maleate citrates) (PAMCs), poly (xylitol-co-citrates) (PXC), and aliphatic biodegradable photoluminescent polymers (BPLPs). The synthesis, development, and applications of these novel polymers will be discussed along with the current trends and future developments in the biomaterials field.

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Recent advancements in preventing teeth health hazard: The daily use of hydroxyapatite instead of fluoride
Roveri N., Foresti E., Lelli M.and Lesci I.G.

Hydroxyapatite (HA) is commonly considered the most promising synthetic biomaterial for biomedical applications in orthopaedic, dental and maxillofacial surgery for its biocompatibility, bioresorption and bioactivity. Only recently a chemical-physical experimental approach has been utilized to investigate the capability of synthetic carbonated hydroxyapatite nanocrystals (CHA) to produce in vivo biomimetic mineral deposition on enamel and dentine surface through a daily use. Demineralised enamel and dentine slabs have been treated in vitro with synthetic biomimetic hydroxyapatite nanocrystals for a few minutes. This induced a surface remineralisation, forming a biomimetic apatite coating on enamel and dentine surface. In fact, enamel remineralisation quickly occurs thanks to the specific chemical-physical characteristics of innovative nanostructured hydroxyapatite particles which closely resemble mineral enamel constituents. Therefore the experimental results suggest the possibility to perform teeth wear-deterioration prevention. Carbonated hydroxyapatite nanocrystals synthesized with tailored biomimetic characteristics for composition, structure, size and morphology can chemically bind themselves on the surfaces of teeth hard tissues, filling the scratches, producing a bound biomimetic apatitic coating, protecting the enamel surface structure. Over the past few decades many products for dental damage prevention (toothpastes, rinses and gels) have been commercialized and patented expressly for the fluoride remineralisation effect. Only recently the numerous applications of hydroxyapatite as bone filler biomaterial for implantation surgery have evidenced innovative and important opportunities for decay prevention through a daily use of oral care products containing hydroxyapatite. The aim of this paper is to review these recent patents and classify them according to their actual possibilities to safeguard teeth health.

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Medical applications of hyperthermia based on magnetic nanoparticles
Boehm F.J. and Chen A.

Nanomedical diagnostic and therapeutic applications based on nanomaterials show great promise for the advancement of medicine. One novel class of these types of nanomaterials includes a range of nanoscale magnetic entities, which may be administered to a patient and then selectively induced to generate heat (hyperthermia) in vivo to selectively eradicate diseased cells and tissues. Potential applications for this highly localized capability may include the thermal deactivation of cancer cells, tumors, other non-cancerous diseased cells and tissues, or blood borne pathogenic microorganisms. In addition, thermally triggered drug release strategies might have the capacity for the specifically targeted delivery of highly potent drugs, albeit in microscopic volumes, directly to disease affected cells. In this review we will survey a range of patents and some related journal articles that describe the latest advancements taking place in this unique and burgeoning area.

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Noninvasive monitoring of intracranial pressure
Popovic D., Khoo M.and Lee S.

Increased intracranial pressure (ICP) is one of the major causes of secondary brain ischemia that accompanies a variety of pathological conditions, most notably, traumatic brain injury (TBI), stroke, and intracranial hemorrhages. However, aside from a few Level I trauma centers, ICP monitoring is rarely a part of the clinical management of patients with these conditions because of the invasiveness of the standard monitoring methods (which require insertion of a catheter into the cranium), additional risks they present for patients, high costs associated with the procedure, and the limited access to trained personnel, i.e., a neurosurgeon. Alternative methods have therefore been sought with which ICP can be measured noninvasively. This article reviews nearly 30 such methods patented over the past 25 years, which included ultrasound "time-of-flight" techniques, transcranial Doppler, methods based on acoustic properties of the cranial bones, EEG, MRI, tympanic membrane displacement, oto-acoustic emission, ophthalmodynamometry, and ultrasound measurements of optic nerve sheath diameter. At present, none of the methods is sufficiently accurate to allow for routine clinical use although several hold promise. Future developments should integrate further refinements of the existing methods, combined use of multiple sensors and/or technologies, and large clinical validation studies on relevant populations.

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Recent patents on light curing of dental materials
de Santis R., Gloria A., Ambrosio L.and Nicolais L,

In the last few decades photo-polymerization, the use of light for curing resins, has been a field of multidisciplinary research particularly involving advanced materials and technologies to restore a tooth. Polymers and composites used in the oral cavity in conjunction with light curing process represent the material and technology objective of this patent review article. The scenario related to polymers, composite formulations and light curing devices in relation to material performance in vitro and in vivo is presented. Current and future developments related to engineering of materials, technologies and clinical approaches to dental restoration will be considered and estimated.

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Devices and methods for closed reduction of diaphyseal fracture
Koo T.K.

Accurate anatomical reduction is a crucial step for operative treatment of diaphyseal fractures of long bone. Failure to realign the fracture site would result in delayed union, malunion, or non-union. Closed reduction is a reduction of a fractured bone by manipulation without incision into the skin. Conventionally, it is conducted under fluoroscopic guidance. Given that the fracture deformity is three-dimensional (3D) in nature, one could imagine how difficult it can be to reduce a 3D deformity based on the static and limited field-of-view two-dimensional fluoroscopic images. In the past few decades, various attempts have been made to improve the closed reduction process. These vary from specially-designed fracture reduction apparatus to robotic assisted reduction. The aim of this paper is to review the advancements and patents in methods and apparatus developed to assist with closed reduction of diaphyseal fractures of long bones. Pros and cons of these approaches will be highlighted.